Button feed control for sewing machines



Jan. 10, 1961 OVB RAUN ETAL BUTTON FEED CONTROL FOR SEWING MACHINES 3Sheets-Sheet 1 Filed Nov. 14, 1958 INVENTORS 05mm an M4 KML W/IVZ Jan.10, 1961 o. BRAUN ETAL 2,967,497

BUTTON FEED CONTROL FOR SEWING MACHINES Filed Nov. 14, 1958 5Shgets-Sheet 2 IN V EN TORS Jan. 10, 1961 o. BRAUN ETAL BUTTON FEEDCONTROL FOR SEWING MACHINES 5 Sheets-Sheet 3 Filed Nov. 14, 1958INVENTORS as mm Ben/w? A?! M. M/VZ BY P A 2,967,497 Patented Jan. 10,1961.

BUTTON FEED CONTROL FOR SEWING MACHINES Oskar Braun and Karl Winz,Kaiserslautern, Pfalz, Germany, assignors to G. M. Pfaft A.G.,Kaiserslantern, Pfalz, Germany, a corporation of Germany Filed Nov. 14,1958, Ser. No. 773,978

Claims priority, application Germany Nov. 16, 1957 6 Claims. (Cl.112-113) The present invention relates to button feeding mechanism forbutton sewing machines of the type comprising a feeding channel forpassing or transporting an array of buttons for insertion into thebutton clamp of the work presser foot of a sewing machine, prior to theinitiation of a button sewing operation.

It has already become known to provide button feeding mechanism forbutton sewing machines, wherein the buttons are introduced into afeeding channel from a storage bin or hopper through a rotary conveyoror the like and advanced or fed intermittently into the button clamp ofthe machine. Indevices of this type, checking and/or control means arerequired in order to cause the buttons to be fed or inserted into thebutton clamp with a predetermined orientation, that is, with the correctside of the buttons facing in a desired (upward) direction. Buttonfeeding mechanism of this type is disclosed and described, for instance,by US. Patent No. 2,505,468, entitled Button Feed Mechanism.

Such button checking mechanism has heretofore been designed primarilyfor use with buttons of the type having one flat or plane surface and anopposite curved or vaulted surface, whereby to enable the use of a feeer or the like mechanical scanning element for effecting a checking and/or aligning of the buttons, in such a manner as to cause all the buttonsintroduced or fed into the button clamp of the sewing machine to beproperly aligned or to face in the proper or desired direction. Whilemechanical button checking and aligning devices of this type have beenemployed successfully in the past, their practical usefulness has beenlimited to one-sided or vaulted buttons and such devices would not, forinstance, be suitable for the checking and/or alignment of buttonshaving parallel plane surfaces, such as the well known mother of pearland the like buttons used in considerable quantities by the industry.

Accordingly, an important object of the present invention is theprovision of a photoelectricchecking or testing device for use inconnection with automatic button feed mechanism for button sewingmachines, being especially designed or suitable for use with buttonshaving plane upper and lower surfaces and exhibiting different surfacecharacteristics or light reflectivity, in particular, buttons having aglossy upper surface of relatively high lustre and a more or less dullor mat lower surface, such as the well known mother of pearl or buttonsconsisting of a like material.

A more specific object of the invention is the provision of aphotoelectric button checking or testing device of the above type,capable of discriminating between different optical surfacecharacteristics of the upper and lower surfaces of the buttons beingtested, especially, though not limitively, for use with buttons of thetype having plane parallel surfaces.

Another object of the invention is the provision of a button checking ortesting device of this type embodying improved means for automaticallyreversing the buttons introduced in the wrong position into the buttonfeeding channel connecting a storage container with the button clamp ofa sewing machine, in such a manner as to automatically align the buttonsin said channel to have a selected (glossy) surface facing in a desired(upper) direction.

Yet another object of the invention is the provision of improved meansfor use in connection with an automatic button checking and aligningdevice of the above type, to suspend the operativeness of the sewingmachine in the absence of any buttons passing or being fed through thefeeding channel of the device.

Another object of the invention is the provision of automatic buttonchecking and reversing mechanism of the above type capable of preventingdefective buttons having no or an insufficient number of holes orperforations from being fed or inserted into the button clamp of thesewing machine.

Still another object of the invention is the provision of automaticbutton checking and/or reversing mechanism for a button sewing machinewhich is both simple in design, as well as efficient in operation, andwhich can be used in conjunction with conventional button sewingmachines. I

The invention, as to its ancillary objects as well as novel aspects andadvantages, will be better understood from the following detaileddescription, taken in reference to the accompanying drawings formingpart of this specification and in which: a

Fig. l is a schematic view of the optical scanning or testing deviceconstructed in accordance with the prin ciples of the invention, beingoperatively associated with a button feeding device, to produce varyingelectric control energy for properly and improperly oriented buttons,respectively, passing through said device;

Fig. 2 is a diagram of the photoelectric control circuit and polarizedelectrical relay as a control device, to produce different controlfunctions by buttonsof undesired orientation, on the one hand, and bydefective buttons having no or an insufiicient number of perforations,on the other hand;

Fig. 3 shows, by way of example, a complete circuit diagram for a buttonsewing machine equipped with automatic button feeding and reversingmechanism and including safety means and ancillary control devices inaccordance with the invention; and

Fig. 4 is a schematic plan view showing the construction of the buttonreversing mechanism controlled by the output of the photoelectricchecking device or button testing circuit in accordance with theinvention.

Like reference characters denote like parts in the different views ofthe drawings.

. With the foregoing objects in view, the invention, according to one ofits aspects, involves generally the provision of a photoelectricscanning or button checking device arranged in cooperative relation tothe button feeding mechanism or channel of a button sewing machine andserving to test or check the buttonsbeing fed successively orintermittently to the button clamp of the machine, to produce varyingelectric output or control energy in dependence upon the varyingcharacteristics or light reflectivity of the upper and lower surfaces,re= spectively, of the buttons being tested by said device. As anexample, the invention is especially suitable for the checking of thewell known mother of pearl or the like buttons having an upper planesurface of relatively higher luster or light reflectivity and having alower plane and mat surface parallel to said first surface of relativelylowlight reflectivity, whereby to result in a substantial differentialof the output currents of said photoelectric device. The output of thephotoelectric device or circuit may serve'to operate a warning signal orindicator, or preferably, to control a button ejecting or reversingdevice,in such a manner as to automatically align the buttons fed intothe button clamp of the sewing machine withtheir correct (glossy) sidepointing in a desired (upper) direction, as will become further apparentas the following description proceeds.

The button reversing device according to the invention may compriseessentially an auxiliary or reversing channel, being in the form of arelatively fiat strip and shunting or by-passing a portion of the mainbutton feeding channel connecting the storage device with the buttonclamp of the sewing machine. A suitable button ejecting device ormechanism being controlled by the output of the photoelectric deviceacts to insert an improperly oriented button into said auxiliary channelat a point proximal to the sewing machine or button clamp, in such amanner that the improperly oriented buttons will be passed through saidauxiliary channel in the reverse direction and reinserted into said mainchannel at a point distal to or remote from the button clamp of thesewing machine. In order to effect a reversal of the buttons passedthrough the auxiliary channel and to re-insert the same into the mainchannel in proper alignment or orientation, the auxiliary channel isbent or twisted by a complete 180 angle, in the manner more clearlyshown by the drawing and understood from the following description.

In order to discriminate between both improperly oriented buttons, onthe one hand, as well as defective buttons having no or an insufficientnumber of holes or perforations, the reflected light or equivalentradiant energy scanning beam, after multiple deflection, such as bymeans of a reversing prism or the like, is passed in a direction axiallyof and through the perforations of the buttons, acting as scanningapertures, and impinged upon the light sensitive surface of aphotoelectric cell or the like device sensitive to the radiant energyand arranged upon the side of the buttons opposite to the side beingscanned or tested by said beam. In this manner, both the buttons facingthe scanning source in the wrong position, as well as defective buttonswill be ejected or by-passed through the auxiliary channel, whereby toprevent their insertion into the button or work clamp of the sewingmachine.

Finally, the photoelectric device may be utilized as a safety means, tosuspend the operativeness of and to prevent damage to the sewing machinein the absence of any buttons passed through the button feeding channel.For this purpose, the entire scanning beam, in the absence of a buttonbeing positioned in the aperture of the scanning device, is impingedupon the photoelectric device by the provision of suitable reflectingmeans, to produce a varying output current serving to operate astop-motion or equivalent safety device of the sewing machine, as willbe further described in the following.

Referring more particularly to Figs. 1 and 4 of the drawings, thenumeral 1 indicates the rear wall of a button feeding channel furthercomprising a pair of bevelled guides 2, one of which may be displaceablerelative to the other end between which are passed or fed a number ofbuttons 3 in a continuous chain or array from a suitable storagecontainer to the button clamp of a sewing machine, as indicated by thevertical arrow in Fig. 4. In Fig. l, the button 3 next to the lower orfirst button of Fig. 4 ready for insertion into the button clamp of thesewing machine, is shown in section and overlying a scanning aperture 4arranged in the rear wall 1. A light beam 6 produced by a suitable lightsource is impinged upon one face of the button 3, said beam forminganangle with the surface of the button, while the reflected beam ispassed through a suitable optical reversing device, preferably areversing prism 7 as shown in the drawing, in such a manner that thebeam, upon multiple reflection by the prism, is passed in a directionsubstantially parallel to the axis of the buttons, to cause a fractionalportion thereof to be transmitted through the holes or perforations 8 ofthe buttons and unto the light sensitive surface of a photoelectricdevice 9, shown in the form of a photoelectric discharge tube of thetype well known in the art.

The output leads 10 and 11 of the photoelectric tube 9 are connected toa suitable biasing or operating voltage source, as indicated byterminals 22 and 23, Fig. 2. Furthermore, the leads 10 and 11 areconnected to the terminals 12 and 13 of a Wheatstone bridge circuitbeing comprised of a pair of fixed resistors 14 and 15 and a pair oftriode or the like amplifying tubes or devices 16 and 17. Connectedbetween one pair of diagonal points 18 and 19 of the bridge circuit is apolarized relay 20 having a movable contact 21 (see also Fig. 3)operable to engage a pair of stationary contacts 82 and 111, uponunbalance of the bridge circuit in either sense or direction,respectively, from the normal or balanced position shown in the drawing.

In other words, the fixed resistors 14 and 15 and the amplifying tubes16 and 17 constitute the branches of a conventional bridge circuit,wherein the relay 20 replaces the conventional galvanometer connected inone of the diagonal bridge circuits. Connected in the coordinateddiagonal bridge circuit, that is, between terminals 22 and 23 is asuitable direct current operating source indicated by the plus and minussigns in the drawing, such as a battery, stabilized rectifier powersupply or the like. The photoelectric tube 9 is connected in a knownmanner to displace the operating point or grid biasing voltage of thetube 16, to vary the internal impedance of the tube, whereas theinternal impedance of the tube 17 is maintained constant by theprovision of a fixed grid return resistor 24.

More specifically, a displacement of the operating point of the tube 16and, in turn, of the internal impedance of the tube results in unbalanceof the bridge circuit, in such a manner as to cause excitation of therelay 20, in either sense and closing of the contacts 82 and 111,respectively, depending upon the sense or direction of the unbalancecurrent, in a manner readily understood. More specifically, the bridgecircuit is energized by the direct current source 22, 23 through acircuit being traced as follows:

(1) Positive terminal 22, terminal 25, differential balancing resistor26, branch circuits (a) including fixed resistor 14, tube 16, fixedresistor 27 and (b) including fixed resistor 15, tube 17, adjustableresistor 28, common terminal 29, terminal 30, balancing resistor 31 andback to the minus terminal 23 of the direct current source.

Resistors 27 and 28 are cathode biasing resistors determining the gridbias of the tubes 16 and 17, the bias of the former being fixed by theresistor 27 and the bias of tube 17 being adjustable by the variableresistor 28, for adjusting or balancing the bridge circuit inconjunction with the potentiometer resistor 31 and the differentialadjusting resistor 26, in the manner to be described presently.

The variable potentiometer resistor 31 is connected to the source 22, 23in series with a pair of fixed voltage divider-resistors 35 and 36 andserves to apply a varying cathode voltage to t.,e tube 16, in a mannerreadily understood. In this manner, it is possible to balance the bridgecircuit, first by a relatively coarse adjustment by means of resistors28 and 31 and subsequently by a fine control or adjustment by means ofthe differential resistor 26, to normally cause the armature 21 of thepolarized relay 20 to be in its neutral or rest position, as shown inthe drawing, for a predetermined intensity of the illumination or amountof radiant energy being impinged upon the photoelectric tube 9.

More specifically, the grid 32 of the tube 16 is nor mally biased to adefinite potential determined, on the one hand, by the internalimpedance of the phototube 9 and the fixed voltage divider resistors 33and 35 connected in-series therewith and energized by the source 22,23.This results -in a positive bias upon the grid 32 varying with theintensity of the illumination and increasing in proportion to anincrease of the illumination of the photoelectric tube.

In addition to the varying positive bias of the grid 32 provided by thephototube 9, a negative grid bias is applied by the cathode biasingresistor 27, said negative bias exceeding the positive bias produced bythe phototube, to normally cause the tube to operate within its negativegrid bias region. As a result, if the illumination of the phototube 9 isincreased or the internal impedance of the tube decreased, the grid biaswill become more positive, resulting in a reduction of the negative biasby the resistor 27 and, in turn, in a decrease of the internal impedanceof the tube 16. In the same manner, a decrease of the illuminationcauses an increase of the impedance of the tube 16. As a result, thebridge circuit being adjusted or balanced for a predetermined or normalintensity or illumination of the phototube 9 becomes unbalanced ineither direction from the balance condition, upon an increase ordecrease of the illumination from its normal value, thus causing aresponse of the polarized relay 20 in either direction or closing ofcontacts 82 or 111, respectively.

Fig. 3 illustrates a complete operating circuit of a button checking andcontrol system for a button sewing machine embodying the principles ofthe invention. Item 50 indicates a three-phase driving motor being fedfrom a three-phase power line R, S, T having a neutral conductor N,through a main or power control switch 51. Simultaneously with theclosing of the switch 51, a first rectifier 52 is connected directly anda second rectifier 53 is connected indirectly by way of a stepdowntransformer 54 to one phase of the power network. While the rectifiers52 and 53 are shown in the drawings in the form of contact bridgerectifiers, they may be of any other suitable type known in the art, wewill be understood. As a result, a DC. voltage appearing at the outputterminals 55, 56 of the rectifier 52 causes the energization of a liftmagnet or solenoid 57 of known construction which serves to operate thebut ton clamp of the sewing machine from its normally lowered or workengaging position to a raised position, against the action of a returnspring, in a manner well known to those skilled in the art. The excitingcircuit for the clamp lift magnet or solenoid 57 is traced as follows:

(II) Positive terminal 55 of rectifier 52, terminal 58, lift magnetwinding 57, terminal 59, movable contact of a foot switch 61, terminal62, movable contact of a pilot switch 64, terminal 65 and back to thenegative terminal 56 of rectifier 52.

Energization of the lift magnet 57 results in a raising of the buttonclamp of the button sewing machine against the action of the clampreturn spring, in a manner well known and pointed out. After insertionof a work piece into the sewing machine, the foot switch 61 or the likeis depressed or operated, resulting in an opening of the Circuit II andclosing of the exciting circuit of a starting magnet or solenoid 67 ofknown construction, said circuit being traced as follows:

(III) Positive terminal 55 of rectifier 52, terminal 58, terminal 68,starting magnet winding 67, movable contact 66 of foot switch 61,contact 1a of a relay A, safety switch 69, terminal 70, terminal 65, andback to the negative terminal 56 of rectifier 52.

The safety switch 69 is mechanically coupled with the clamp liftingmagnet 57, as indicated by the dot-dash line 69' in the drawing, in sucha manner that it will be opened during the raised position of the buttonclamp and closed in the normal or lowered position of the clamp, asshown in the drawing.

As a result of the operations described, the sewing machine is startedby the operation of a suitable coupling device by the magnet or solenoid67, to establish driving connection between the machine and thecontinuously running driving motor 50, in a manner well known andunderstood. The sewing machine automati cally performs a button sewingoperation or program. Immediately upon starting of the machine, thecontact 63 of the pilot switch 64 is opened, said switch being connectedin a known manner to an operative organ of the sewing machine (notshown). As an example, the switch 64 which may be connected with thecoupling mechanism or any other operative parts of the machine, assumingthe position shown in the drawing during the inoperative or restcondition of the sewing machine and being automatically operated to anopen position to interrupt contact 63 and to close a further contact 71,to be described presently. After the operation of the machine has beenstarted, the foot switch 61 is released, whereby to interrupt theCircuit III, while maintaining open the Circuit II due to theinterruption of the contact 63.

Simultaneously with the opening of the contact 63 by the pilot switch64, the contact 71 closes a charging cir-' cult of a capacitor 74 beingconnected to the output terminals of the rectifier 53 and traced asfollows:

(IV) Positive terminal 72 of the rectifier 53, terminal 75, capacitor74, terminal 76, switch contact 71, terminal 77 and back to the negativeterminal 73 of rectifier 53.

As a result, the capacitor 74 is charged by the rectifier 53 during abutton sewing operation of the machine. Upon completion of the buttonsewing operation, the machine is automatically stopped in a manner wellknown, resulting in an opening of the charging circuit 4 by opening ofthe contact 71 by the pilot switch 64. At the same time the contact 63of the switch 64 is again closed, whereby to re-energize the button liftmagnet 57 through Circuit II and to result in a renewed lifting orraising of the button clamp of the machine. Upon completion of thisoperation, a further switch 78 being mechanically coupled with thebutton clamp is closed to result in a discharge of the capacitor 74through a cir-' cu-it traced as follows:

(V) Positive terminal of capacitor 74, terminal 75, terminal 79,coupling magnet 80, switch contact 78 and back to the negative terminalof the capacitor 74.

The coupling magnet 80 or equivalent electrically operated actuatingdevice serves to operate in a known manner the button feed mechanism,whereby to advance the buttons in the feeding channel and to introducea; new button into the button clamp of the sewing machine. During thisoperation of the button feeding device, a locking or safety switch 81shunting the foot switch terminals 59 and 62 in the Circuit II is closedto shortcircuit said terminals, thereby to prevent the operationpression of the foot switch 61 causes the initiation of a new operatingcycle as described hereinbefore.

The buttons 3 within the button feeding channel 1 are advanced by thebutton feeding mechanism by a distance equal to the diameter of onebutton, after the button at the extreme end of the channel has been fedor introduced into the button clamp, whereby the next following buttonis moved to a position overlying the scanning aperture 4,,

Fig. 4, for testing or checking by the photoelectric device; If thelight beam 6 impinges in the manner described. upon the upper or glossyside of the button 3 positioned in the scanning aperture, that is, ifthe button being scanned passes through the feeding channel 1 in the.

desired or proper orientation, the light beam upon reversal.

by the prism and passage through the perforation of the buttons willresult in an illumination of the phototube 9' maintaining the bridgecircuit in a balanced condition, as; described, whereby, in turn, tocause the armature 21 of '7 the.relay 20 to assume a neutral positionbetween the contacts 82 and 111, a shown in the drawing.

On;the other hand, if a button 3 during scanning by the light beam 6 isin the wroing or upside down position, the intensity of the reflectedlight beam will be weakened due to the reduced light refiectively of thebutton surface, in such a manner as to result in a reduction of thenegative bias of the grid 32 of the amplifier tube 16, is the mannerdescribed hereinbefore, thus, resulting in a disturbance of the balanceor equilibrium of the bridge circuit and, in turn, in a response of therelay 20. As an example, the connections and adjustment of the circuitmay be such that in the case of a button being in the wrong position,that is, with the illumination of the phototube 9 being reduced, therelay 20 will respond to close its contact 82, Fig. 3, whereby toenergize and operate a further relay B by a previously charged capacitor83 through a circuit traced as follows:

(VI) Capacitor 83, terminal 84, terminal 85, terminal 86, relay windingB, contact 82, contact arm 21, terminal 87 and back to the capacitor 83.

The capacitor 83 is normally charged, that is, while the relay contact21 is in its neutral position through a charging circuit traced asfollows:

(VII) Positive terminal 72 of rectifier 53, terminal 75, terminal 79,terminal 86, terminal 85, terminal 84, capacitor 83, terminal 87,charging resistor 88, terminal 89, terminal 90, terminal 77 and back tothe negative terminal 73 of the rectifier 53.

I As a result, energization of relay B closes its contact 1b, whereby toestablish an exciting circuit for a button reversing magnet or solenoid91, being traced as follows:

(VIII) Positive terminal 55 of the rectifier 52, terminal 58, terminal68,terminal 92, reversing magnet winding 91, contact 1b, terminal 93,terminal 70, terminal 65 and back to the negative terminal 56 ofrectifier 52.

The solenoid 91 forms part of the button reversing mechanism shown inFig. 4. Referring to the latter, the main feeding channel 1 is providedwith an ingress opening 100 adjacent to one side of the scanningaperture 4 upon the opposite side of which is arranged a sliding member102 connected with the armature of the magnet 91 through a suitablelinkage or the like coupling mechanism 103, 104, 105. As a result,energization of the magnet or solenoid 91 will result in a displacementof the slide 162 in the direction shown by the arrow, whereby to ejectand introduce a button 3 under test into the reversing device 101. Thelatter consists essentially of a strip-like auxiliary feeding channel107 having its input connected to the opening 100 located proximal tothe button clamp of the sewing machine and having its output connectedto a further opening 108 of the main feeding channel 1 at a point distalto or remote from the button clamp of the machine. A resiliently mountedblocking lever 106 which is briefly deflected during the insertingoperation of a button into the auxiliary channel 107, serves to engageand hold the inserted button in the position adjoining the opening 100,in the manner of a click-stop or the like arresting device.

As pointed out, the button reversing device is comprised essentially ofa semi-circular guide or auxiliary channel 107 having its outputconnected to the opening 108 of the main feeding channel 1. Disposedadjacent to the latter opening is a further retaining lever 109 servingto arrest or fix the position of the button next to the opening 108, ina manner similar to the function of the lever 106. The guide or channel107 is bent or twisted by a full 180 angle, whereby to result in areversal of the buttons passed therethrough and being re-inserted intothe main feeding channel after the auxiliary channel has, been filledwith a complete array of buttons, as will be understood. As a result,buttons having been originally introduced into the main channel in thewrong orientation will .be automatically reversed, in such a mannerlasto cause buttonsof a desired position or orienta- 8 tion only to be fedintothebutton clamp. of the sewing machine.

More specifically, energization of the reversing solenoid 91.connectedin the Circuit VIII will result man improperly oriented button beingejected and insertedlinto the reversing channel .by the slide 102 orequivalent ejecting mechanism, whereby to cause the next followingbuttonto be advanced to a position overlying the scanning aperture 4. If thisbutton has a proper orientation, the balance of the bridge circuit willbe maintained and the slide 102'. remain in its rest or inoperativeposition. It is furthermore possible, according to an improved featureof the invention, to determine whether the buttons 3 introduced into thechannel 1 are defective in having an improper numberof perforations 8.Thus, if, in the case of a defective button, one of the perforationsshould be missing, this will result in a decrease of the amount of lightimpinged upon the photoelectric cell 9, whereby to initiate the samecontrol operation by ejecting the defective buttons by the slide 102 orthe like ejecting mechanism. The same would apply to defective buttonshaving no perforations.

Referring againto Fig. 1, there is further shown a mirror or reflectorarranged on the side of theehannel 1 opposite to the lightsource 5,whereby in the absence of buttons passing through the feeding channel,the beam 6 traverses the aperture 4 in fullstrength and will be rcflected by the mirror 110 unto the sensitive surface of thephotoelectric cell 9. Since this results in an increase of theillumination of the photoelectric cell in respect to the normal orbalance condition of the bridge circuit, the polarized relay 20 nowcloses its contact 111, Fig. 3, thus in turn closing the excitingcircuit of a further relayA traced in the following:

(IX) Capacitor .83, terminal 84, terminal 85, relay A, contact 111,contact 21, terminal 87 and back to the capacitor 83. j

Energization of the relay A results in the opening of the relay contact121, whereby to open the Circuit III and to prevent energization of thestarting solenoid 67 by operation of the foot switch61. The,operativeness of the sewing machine is thereby suspended, as long as nobuttons are fed through the channel 1. At the same time, a furthercontact 2a of ,therelay A closes the circuit ,of a pilot or indicatorlamp 112 connected in a circuit traced as follows: j

(X) Positive terminal 72 of rectifier 53, terminal 75, terminal 79,terminal 113, lamp 112, contact 211, terminal 9t), terminal '77 and backto the negative terminal 73 of the rectifier 53. j i j The relay A is sodesigned as to remain energized after the full discharge of thecapacitor 83 through a holding circuit traced as follows:

(XI) Positive terminal 72 of rectifier 53, terminal 75, terminal 79,terminal 113, terminal 86, terminal 85, relay A, contact 111, contact21, terminal 87, resistance 88, terminal 89, terminal 90, terminal 77and backto the negative terminal 73 of rectifier 53. i

As soon as renewed feeding of buttons is commenced, the beam 6 becomesagain weakened, whereby the relays A and 20 are released, resulting inthe re-establishment of the operativeness of the sewing machine andcontrol device. This condition is indicated by the extinction of thelamp 112 by interruption of the contact 2a in the Circuit X.

The relay B is so designed as to be unable to maintain its excitationthrough resistance 83 during clos'ng of the contact 82, after thecapacitor 83 has been fully discharged. As a result, the reversingmagnet 91 is energized during a short period or pulse only, in such amanner as to eject a single button only and to al'ow the remainingbuttons to be advanced to the next following position by a distanceequal to the diameter of the buttons, beforeinitiating a renewed buttontesting operation. i

In the foregoing, the invention has been described with reference to aspecific illustrative device and circuit. It will be evident, however,that numerous modifications and variations, as well as the substitutionof equivalent devices or circuits for those shown and described hereinfor illustration, may be made without departing from the broader scopeand spirit of the invention as set forth in the appended claims. Thespecification and drawings are accordingly to be regarded in anillustrative rather than in a limiting sense.

We claim:

1. In button feeding mechanism for sewing machines including a feedingchannel and means for feeding a consecutive series of perforated buttonshaving opposite faces of relatively high and relatively low reflectivityto said machine, a control system comprising a source arranged at oneside of said channel to direct a radiant energy scanning beam upon andat an angle with the surface of said buttons, means to deflect said beamupon reflection by said buttons, to cause the deflected beam to passsubstantially axially of and through the perforations of said buttons,and radiant energy sensitive means arranged at the opposite side of saidchannel to be impinged by said beam, to produce an output current havinga predetermined value for buttons oriented with their surface of highreflectivity facing said source and having perforations passing apredetermined fraction of said beam and decreasing for buttons beingoriented with their surface of low reflectivity facing said sourceand/or having perforations passing a fraction of said beam less thansaid predetermined fraction.

2. In button feeding mechanism for sewing machines including a feedingchannel and means for feeding a consecutive series of perforated buttonshaving opposite faces of relatively high and relatively low lightreflectivity to said machine, a control system comprising a light sourcearranged at one side of said channel with means to project a scanninglight beam upon and at an angle with the surface of said buttons, meansto deflect said beam upon reflection by said buttons, to cause thedeflected beam to pass substantially axially of and through theperforations of said buttons, and a photoelectric device arranged at theopposite side of said channel to be impinged by said beam, to produce anoutput current having a predetermined value for buttons oriented withtheir surface of high reflectivity facing said source and having apredetermined number of perforations and decreasing for buttons beingoriented with their surface of low reflectivity facing said source and/or having perforations less than said predetermined number.

3. A button feed control system as claimed in claim 2 including buttonreversing means comprised of an auxiliary channel having inlet meansconnected to said feeding channel at a point adjacent to the buttonsbeing scanned by said source and having outlet means connected to saidfeeding channel at a point distal to said first point in respect to saidmachine, said auxiliary channel being bent by an angle of 180, to effecta reversal of the buttons passing therethrough, and actuating means forsaid inlet means controlled by said current, to introduce buttons ofpredetermined orientation into said auxiliary channel.

4. A button feed control system as claimed in claim 3 including furtherreflecting means arranged at the side of said feeding channel oppositefrom said source, to directly impinge said beam upon said device in theabsence of a button in said feeding channel, differential translatingmeans connected to said photoelectric device being normally balanced forbuttons passing through said feeding channel with their surface of highreflectivity facing said source and adapted to produce first and secondoutput currents upon unbalance in different directions in the absence ofa button in said feeding channel, on the one hand, and upon passage of abutton through said channel with its surface of low reflectivity thereoffacing said source and/or having insufficient perforations, on the otherhand, a button reversing channel by-passing said feeding channel andhaving inlet means adjacent to the button in said feeding channel beingscanned by said source, means to effect the stoppage of said machine,and further means to actuate said last means and said inlet means bysaid first and second output currents, respectively.

5. In button feeding mechanism for sewing machines having a feedingchannel and means for intermittently feeding a consecutive series ofperforated buttons having opposite faces of relatively high andrelatively low reflectivity to said machine, a control system comprisinga light source arranged at one side of said channel with means toproject a scanning light beam upon and at an angle with the surface ofsaid buttons at a predetermined point of said channel,.a multiplereflecting device to deflect said beam upon reflection by said buttons,to cause the deflected beam to pass substantially axially of and throughthe perforations of said buttons, a photoelectric device arranged at theopposite side of said channel to be impinged by said beam, to produce anoutput current having a predetermined value for buttons having a firstorientation with their surface of high reflectivity facing said sourceand having a predetermined number of perforations and decreasing forbuttons having a second orientation with their surface of lowreflectivity facing said source and/or having perforations less thansaid predetermined number, and a button reversing auxiliary channelhaving inlet means connected to said feeding channel at a point adjacentto said first point and having outlet means connected to said feedingchannel at a point distal to said first point in respect to saidmachine, and actuating means for said inlet means controlled by saidcurrent, to introduce buttons of said second orientation into saidreversing channel.

6. A button feed control system as claimed in claim 5 including furtherreflecting means arranged at the side of said feeding channel oppositefrom said source, to directly impinge said beam upon said device in theabsence of a button in said feeding channel, to increase said outputcurrent beyond said predetermined value, a polarized relay connected tosaid device being balanced to a neutral position by said predeterminedoutput current and including means to establish a first and a secondcontrol current, respectively, by an unbalance in one direction by theabsence of a button in said feeding channel, on the one hand, and by anunbalance in the opposite direction by a button oriented according tosaid second orientation and/or a button with insufficient perforations,on the other hand, motion stoppage means for said machine, and furthermeans to operate said last means and said actuating means by said firstand second control currents, respectively.

References Cited in the file of this patent UNITED STATES PATENTSSwitzerland Mar. 2, 1953

